Machine for twisting metal wires



April 3, 1935. K. J. JENSEN 1,998,582

MACHINE FOR TWISTING METAL WIRES Filed March 5, 1934 El g. 2.

Patented Apr. 23, 1935 UNITED j STATES PATENT OFFICE MACHINE FOR TWISTING METAL wines Karl Johan-Jensen, Nydalcn, V. Aker, near Oslo Norway, assignor to Gunnar Oslo, Norway Application March 3, 1934, Serial No. 713,871

Larsen whist:

In Germany December 22, 1933 4 Claims.

5 helical nails or the like.

Machines of this type generally comprise two drums for taking up the untwisted and the twisted wire respectively, the axes of said drums being adapted to perform a rotativ'e movement relative to each other in parallel planes. In passing from one drum to the other the wire to be twisted is held between guiding rollers, which are stationary relative to the drum from which the wire is unwound, and the twisting of the-wire accordingly'takes place between these guiding rollers and the second drum, on to which the wire is wound.

It has been found in practice that it is very important in order to obtain a satisfactory effect by the use of helically wound nails that the pitch of the helical twisting is absolutely uniform and is maintained within certain definite limits varying with the thickness of the profile wire used.

In machines of the kind specified it is not possible to obtain a uniform pitch along the length of the wire to be twisted, as hard wires of the kind adapted for use in the manufacture of nails have a varying degree of resistance to torque along their length, and when the twi ting takes place over a considerable length of wire, such as is the case in machines of the type specified, the softer parts ofthe wire when appearing between the guiding rollers and the receiving drum will be twisted with a shorter pitch than the harder parts of the wire.

In order to avoid this drawback the twisting of the wire in accordance with the present invention is done bymeans of a pair of stationary guiding rolls, gripping the wire and preventing its rotation. Spaced from these rolls, a drum is arranged winding up the twisted wire. Between this drum and the guiding rolls a pair of grooved rolls is arranged spaced from and offset toward each other. The wire has to pass these rolls on its way from the guiding rolls to the drum and is deflected by these rolls in an acute angle. If rotating the drum around its own axis and, furthermore, both the drum and the pair of the grooved rolls around another axis lying substantially in the direction of the path of the wire between the guiding rolls, the wire is twisted while gliding on one of the rolls of the roller-pair which lies on the side of the guiding rolls.

-Hereby it is obtained that the twisting of the wire takes place on a relatively very short length of wire, whereby the risk of having wire with different hardness exposed to twisting torque at the same time is considerably reduced.

In accordance with the invention one of thesaid sets of guiding rollers comprises two or more rollers placed a certain distance apart and so located with regard to each other and with re- RElSSUED OCT 8" i940 gard to the longitudinal axis of the wire that the latter in passing the rollers follows the circumference thereof over a certain arc, whereby a bending of the wire takes place around the particular roller so that the wire is deflected in an acute angle. The rollers are provided with smoothly curved guiding grooves in order to permit the wire to rotate around its axis relatively to the roller.

The set of rollers over which the wire is bent will exert a certain torque on the wire, and as this torque will depend on the friction between roller and wire, the torque exerted by the rollers will be in proportion to the hardness of the particular part of the wire under treatment, owing to the fact that the elastic resistance of the wire against being bent over the rollers will be in proportion to the hardness of the particular part of wire under treatment.

In this manner it is obtained that the twisting torque exerted on the wire will be in proportion to the resistance of the wire against being twisted, whereby the uniform twisting pitch is obtained in the finished product irrespective of the variation in hardness along the length of the wire.

Further features of the invention will be apparent from the following specification with ref-'- erence to the drawing, of which Fig. l is a side ViCW of a machine in which the invention is embodied, whereas Fig. 2 is a side view at a larger scale of a modified form of twisting rollers.

Referring to Figure 1 the profile wire I is unw und from a drum having a stationary axis (not shown on the drawing). The twisted wire is wound on to a drum 2, which is rotatably mounted on the frame or yoke 3, which is adapted to rotate around an axis perpendicular to the axis of the drum.

The profile wire I passes the stationary hollow trunnion 4 and between stationary guiding rollers 5, II which are adapted togrip the profile wire securely between them. At a short distance from rollers 5, I l the profile wire I passes between a. second set of guiding rollers l3 l4 carried by the support 6 which is secured to the rotating frame of the arrow shown in Fig. 2) takes place on the short stretch between rollers 5, H and rollers l3, l4.

In order to secure a uniform feeding of the wire the same is wound on one end of the conical drum 2, the several windings slipping gradually along the conical surface of the drum.

In order to be able to control the pitch of the twisting the rotation of drum 2 is derived from a countershaft 8, which is adapted to be.

brought into engagement with any one of a num ber of stationary gears I0 during the rotation of the frame 3.

By using gear wheels 9 of different diameter the ratio of rotation of drum 2 and frame 3 may be varied in order to vary the pitch of the twist.

In accordance with the invention the set of guiding rollers 5 shown in Fig. 2 comprises the usual rollers I I, I2, having profile grooves adapted to grip the wire securely between them. The second set of rollers carried by the support 6 however comprises two rollers l3, M, which are mounted at a certain distance from each other and around which the wire is bent at certain angles, so that the wire will be in contact with each roller for a certain definite arc of its circumference.

As it is to be seen from the drawing, the wire is deflected from its horizontal path in an acute angle at, being considerably smaller than and must not exceed 40-50". It results in that the wire may rotate relatively to the roll i 3, while passing it, and thereby the following advantage is obtained. The resistance of the wire to bending increases with its hardness and, consequently, the force for bending the wire exercised by .the drum 2 while rotating around its own axis automatically increases correspondingly. Thereby the friction is increased between the harder wire and the roll and thereby the resistance to rotation of the wire on the periphery of the roll l3. Because of the fact that the drum 2 rotates also around another axis arranged about perpendicularly to its own axis and lying in the direction of the horizontal path of the wire between the stationary guiding rolls ll, l2, the mechanism for rotating the drum 2 around the second horizontal axis automatically and momentarily increases the momentum of torsion corresponding to the increased resistance to torsion. Thereby the advantage is secured that the twisting torque becomes indeed directly proportionate to the hardness of the wire.

The grooves of said rollers I3, 14 have a smooth curved cross section so as to permit the wire to slip in the grooves about the axis of the wire.

As explained above this arrangement of guiding rollers l3, M will have the effect of exerting an increased torque on the wire when hard parts of the wire arrive between the rollers, as these hard parts of wire will be pressed more strongly against the rollers owing to being bent partly about them than will be the case with soft parts of wire.

The rolls l3, l4 may preferably be adapted to be adjusted to different positions with regard to the other roller and the horizontal path of the wire.

Although the second set of rollers as illustrated on the drawing does only comprise two rollers l3, l4, three or more rollers may be used in some cases.

I claim:

1. In a machine for continuously twisting wire,

a pair of stationary guiding rolls adapted to grip the wire and to prevent its rotation, a drum spaced from said guiding rolls and being adapted to wind up the twisted wire, a pair of grooved rolls spaced from, and offset towards, each other and pair of grooved rolls around another axis lying substantially in the direction of the path of the wire between said guiding rolls.

2. In a machine for continuously twisting wire, a pair of stationary guiding rolls gripping the wire and preventing its rotation, a drum spaced from said guiding rolls and being adapted to wind up the twisted wire, means for rotating said drum around its own axis and another one substantially perpendicular to the first one and lying substantially in the direction of the path of the wire between said guiding rolls, a pair of rolls having circumferential guiding grooves of smoothly curved cross section adapted to grip the wire without preventing its rotation and being spaced from, and offset towards, each other between said stationary guiding rolls and said drum, thereby bend- 1 ing the wire from its path in an acute angle, and j means for rotating said pair of rolls around an axis lying substantially in the direction of the path of the wire between the stationary guiding rolls.

In a machine for continuously twisting wire, a pair'of stationary guiding rolls gripping the wire and preventing its rotation, a drum spaced from said guiding rolls and being adapted'to wind up the twisted wire, means for rotating said drum around its own axisand another one substantially perpendicular to the first one and lying substantially in the direction of the path of the wire between said guiding rolls, a pair of rolls having circumferential guiding grooves of smoothly curved cross section adapted to grip the wire without preventing its rotation and being spaced from, and ofiset towards, each other between said stationary guiding rolls and said drum, thereby bending the wire from its path in an acute angle so that the power of torsion may overcome the resistance to rotation due to friction between the wire and said roll, and means for rotating said pair of rolls around an axis lying substantially in the direction of the path of the wire between the stationary guiding rolls.

4. In a machine for continuously twisting wire, a pair of stationary guiding rolls gripping the wire and preventing its rotation, a drum spaced from said guiding rolls and being adapted to wind up the twisted wire, means for rotating said drum around its own aXis and another one substantially perpendicular to the first one and lying substantially in the direction of the path of the wire between said guiding rolls, a pair of rolls having circumferential guiding grooves of smoothly curved cross section adapted to grip the wire without preventing its rotation and being spaced from, and offset towards, each other between said stationary guiding rolls and said drum, thereby bending the wire from its path in an acute angle of less than'50, and means for rotating said pair of rolls around an axis lying substantially in the direction. of the path of the wire between the stationary guiding rolls.

KARL JOHAN JENSEN. 

